<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style type="text/css">
    * {
        margin: 0;
        padding: 0;
    }
    ul {
        list-style: none;
    }
    body {
        background: url('../images/wx.jpg') repeat-x;
    }
    .nav {
        height: 75px;
    }
    .nav li {
        float: left;
        margin: 0 10px;
        padding-top: 21px;
    }
    .nav li a {
        display: block;
        background: url(../images/to.png) no-repeat;
        color: #fff;
        font-size: 14px;
        line-height: 33px;
        padding-left: 15px;
        text-decoration: none;
    }
    .nav li a:hover {
        background-image: url(../images/ao.png);
    }

    .nav li a:hover span {  /* 鼠标经过a a里面的span 也要变换背景 */
        background-image: url(../images/ao.png);
    }
    .nav li a span {
        display: block;
        line-height: 33px;
        background: url(../images/to.png) no-repeat right center;
        padding-right: 15px;
    }
    </style>
</head>
<body>
    <div class="nav">
        <ul>
            <li>
                <a href="#">
                    <span>首页</span>
                </a>
            </li>
            <li>
                <a href="#">
                    <span>帮助与反馈</span>
                </a>
            </li>
            <li>
                <a href="#">
                    <span>公众平台</span>
                </a>
            </li>
            <li>
                <a href="#">
                    <span>帮助与反馈</span>
                </a>
            </li>
            <li>
                <a href="#">
                    <span>帮助与反馈</span>
                </a>
            </li>
        </ul>
    </div>
</body>
</html>